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Daily Report

Daily Cardiology Research Analysis

01/29/2025
3 papers selected
3 analyzed

A multicountry RCT in Africa showed that starting low-dose dual antihypertensive therapy is noninferior to stepped monotherapy, informing first-line hypertension management. A mechanistic study identified PP2A activation as a promising therapeutic strategy to prevent thoracic aortic aneurysm progression in Marfan syndrome by suppressing mTOR signaling. A large cluster randomized crossover trial found that restricting intraoperative benzodiazepines during cardiac surgery did not significantly red

Summary

A multicountry RCT in Africa showed that starting low-dose dual antihypertensive therapy is noninferior to stepped monotherapy, informing first-line hypertension management. A mechanistic study identified PP2A activation as a promising therapeutic strategy to prevent thoracic aortic aneurysm progression in Marfan syndrome by suppressing mTOR signaling. A large cluster randomized crossover trial found that restricting intraoperative benzodiazepines during cardiac surgery did not significantly reduce postoperative delirium.

Research Themes

  • Hypertension treatment strategies and global health
  • Translational mechanisms in aortopathy (PP2A–mTOR axis)
  • Perioperative neurocognitive outcomes in cardiac surgery

Selected Articles

1. Treatment Strategies to Control Blood Pressure in People With Hypertension in Tanzania and Lesotho: A Randomized Clinical Trial.

80.5Level IRCT
JAMA cardiology · 2025PMID: 39878989

In 1,268 adults with untreated hypertension in Lesotho and Tanzania, initiating low-dose dual therapy (amlodipine 5 mg + losartan 50 mg) was noninferior to stepped monotherapy for achieving target blood pressure at 12 weeks. Low-dose triple therapy did not significantly outperform monotherapy, and wide confidence intervals suggest uncertainty regarding small effect sizes.

Impact: This pragmatic RCT directly informs first-line antihypertensive strategies in African settings, supporting WHO guidance for early dual therapy while tempering expectations for immediate benefits of triple therapy.

Clinical Implications: Initiating low-dose dual therapy is a viable and noninferior approach for first-line treatment in uncomplicated hypertension in resource-limited settings; triple therapy may be reserved until further evidence clarifies benefits. Implementation should consider medication access and follow-up capacity.

Key Findings

  • At 12 weeks, 56% (2-pill) vs 51% (stepped monotherapy) reached BP targets; noninferiority met (aOR 1.18; 95% CI 0.87–1.61).
  • Low-dose triple therapy: 57% achieved target vs 49% with stepped monotherapy; not statistically superior (aOR 1.28; 95% CI 0.91–1.79).
  • Findings support WHO guidance to start dual therapy and highlight uncertainty (wide CIs) regarding added benefits of triple therapy.

Methodological Strengths

  • Multicenter randomized design across two African countries with pragmatic implementation.
  • Predefined noninferiority and superiority analyses with intention-to-treat approach and multiple imputation for missing data.

Limitations

  • Open-label design and short 12-week follow-up limit detection of long-term differences.
  • Wide confidence intervals preclude ruling out clinically meaningful effects of additional pills.

Future Directions: Longer-term, larger-scale trials in diverse LMIC settings should evaluate sustained BP control, adherence, safety, and hard outcomes, and assess cost-effectiveness of dual vs triple therapy initiation.

IMPORTANCE: Hypertension is the primary cardiovascular risk factor in Africa. Recently revised World Health Organization guidelines recommend starting antihypertensive dual therapy; clinical efficacy and tolerability of low-dose triple combination remain unclear. OBJECTIVES: To compare the effect of 3 treatment strategies on blood pressure control among persons with untreated hypertension in Africa. DESIGN, SETTING, AND PARTICIPANTS: This was an open-label, parallel, 3-arm randomized clinical trial to evaluate noninferiority of a strategy starting 2 pills vs full-dose monotherapy with stepped escalation (noninferiority margin 10%) and superiority of starting low-dose 3 pills vs monotherapy allowing for monthly up titration. Recruitment lasted from March 5, 2020, to March 30, 2022. The setting was 2 hospitals in rural Lesotho and Tanzania. Participants included nonpregnant Black African individuals 18 years and older with uncomplicated, untreated hypertension (standardized office blood pressure ≥140 mm Hg systolic or ≥90 mm Hg diastolic). INTERVENTIONS: Participants were randomized 2:2:1 to stepped monotherapy (amlodipine, 10 mg, with escalation to add hydrochlorothiazide if needed), 2-pill strategy (amlodipine, 5 mg; losartan, 50 mg), or 3-pill strategy (amlodipine, 2.5 mg; losartan, 12.5 mg; hydrochlorothiazide, 6.25 mg). Drugs were up titrated monthly until reaching the target blood pressure (≤ 130/80 mm Hg for participants aged <65 years; ≤140/90 mm Hg for those aged ≥65 years). MAIN OUTCOMES AND MEASURES: Proportion of participants reaching target blood pressure at 12 weeks. RESULTS: Of 1761 participants screened, 1268 were enrolled (median [IQR] age, 54 [45-65] years; 914 female [72%]), with 505 in the monotherapy cohort, 510 in the 2-pill cohort, and 253 in the 3-pill cohort. In noninferiority analyses, 207 of 370 participants (56%) receiving the 2-pill strategy and 173 of 338 participants (51%) receiving the stepped monotherapy strategy achieved the blood pressure target (adjusted odds ratio [aOR], 1.18; 95% CI, 0.87-1.61), fulfilling noninferiority. In superiority analyses after multiple imputation for missing outcome data, 57% of participants receiving the 3-pill strategy, 55% receiving the 2-pill strategy, and 49% receiving the stepped monotherapy strategy reached the target blood pressure (aOR, 1.24; 95% CI, 0.94-1.63; P = .12 and aOR, 1.28; 95% CI, 0.91-1.79; P = .16 for the 2-pill and 3-pill vs stepped monotherapy strategies, respectively). CONCLUSIONS AND RELEVANCE: Results of this randomized clinical trial show that in 2 African settings, for adults with uncomplicated untreated hypertension, a strategy starting a 2-pill low-dose treatment was noninferior to starting stepped monotherapy. Two-pill and 3-pill low-dose strategies were not superior to stepped monotherapy. Wide CIs preclude the ability to rule out potentially clinically important effects of the additional pill strategies for hypertension control. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04129840.

2. PP2A Attenuates Thoracic Aneurysm and Dissection in Mouse Models of Marfan Syndrome.

78.5Level IVBasic/Mechanistic Research
Hypertension (Dallas, Tex. : 1979) · 2025PMID: 39878024

In Marfan mouse models, oral activation of PP2A with DT-061 reduced aortic root and ascending aorta expansion, limited medial hypertrophy and elastin breakdown, and decreased metalloproteinase activity. Mechanistically, PP2A activation suppressed mTOR signaling and smooth muscle dedifferentiation, suggesting a disease-modifying therapeutic avenue.

Impact: Identifies PP2A activation as a tractable, small-molecule strategy to counteract mTOR-driven aortopathy in Marfan syndrome, bridging mechanistic insight with translational potential.

Clinical Implications: While preclinical, the data support development of PP2A activators as potential disease-modifying therapies for heritable aortopathies (e.g., Marfan). Clinical translation will require safety profiling, dose-finding, and biomarker-driven trials.

Key Findings

  • PP2A activity was reduced and mTOR signaling increased in human and mouse Marfan aortas.
  • DT-061 increased PP2A activation and reduced aortic root/ascending aorta expansion, medial hypertrophy, elastin breakdown, and MMP activity.
  • Mechanistic analyses indicate suppression of mTOR signaling and smooth muscle cell dedifferentiation as drivers of therapeutic effect.

Methodological Strengths

  • Use of two independent Marfan mouse models with convergent results.
  • Multimodal assessments (echocardiography, histology, RNA-seq, WB, immunostaining) supporting mechanistic inference.

Limitations

  • Preclinical animal models without human efficacy or safety data.
  • Potential off-target effects of systemic PP2A activation require careful evaluation.

Future Directions: Advance to IND-enabling studies: pharmacokinetics, toxicology, dose-ranging, and biomarker development; explore synergy or add-on to current Marfan therapies (e.g., ARBs, beta-blockers).

BACKGROUND: Recent studies show that hyperactivation of mTOR (mammalian target of rapamycin) signaling plays a causal role in the development of thoracic aortic aneurysm and dissection. Modulation of PP2A (protein phosphatase 2A) activity has been shown to be of significant therapeutic value. In light of the effects that PP2A can exert on the mTOR pathway, we hypothesized that PP2A activation by small-molecule activators of PP2A could mitigate AA progression in Marfan syndrome (MFS). METHODS: Two distinct mouse models of MFS underwent daily oral administration of small-molecule activators of the PP2A compound DT-061 to assess its therapeutic potential. Echocardiography was performed to monitor the growth of the aortic root and ascending aorta. Histological evaluation was performed to assess alterations in the vascular wall. RNA-sequencing, Western blot, and immunostaining were performed to decipher the underlying mechanisms by which DT-061 suppresses AA progression. RESULTS: PP2A activity decreased, while mTOR activity increased in both human and mouse aortas with MFS. Concordantly, oral administration of DT-061 increased PP2A activation, reducing aortic expansion in Marfan mice. DT-061 treatment also mitigated medial hypertrophy, elastin breakdown, and extracellular matrix deterioration in the ascending aorta, along with decreased metalloproteinase activities. Mechanistic studies suggest that DT-061 suppresses mTOR signaling and smooth muscle cell dedifferentiation, contributing to its effects on thoracic aortic aneurysm and dissection progression. CONCLUSIONS: These studies demonstrate a pathological role of PP2A activity loss in the cause of MFS and implicate that activation of PP2A may serve as a novel therapeutic strategy to limit MFS progression, including aortic aneurysm formation.

3. Benzodiazepine-Free Cardiac Anesthesia for Reduction of Postoperative Delirium: A Cluster Randomized Crossover Trial.

76.5Level IRCT
JAMA surgery · 2025PMID: 39878960

Across 19,768 cardiac surgery patients, an institutional policy restricting intraoperative benzodiazepines did not significantly reduce postoperative delirium within 72 hours (aOR 0.92; P=0.07). No increase in patient-reported intraoperative awareness was detected, suggesting safety but limited efficacy at the policy level.

Impact: Provides definitive large-scale randomized evidence on a common anesthesia practice, informing guideline discussions about benzodiazepine use and highlighting the need for patient-level targeting.

Clinical Implications: Routine institutional restriction of intraoperative benzodiazepines may not meaningfully reduce delirium; consider individualized strategies (e.g., risk stratification, multimodal delirium prevention) while maintaining vigilance for awareness.

Key Findings

  • Delirium within 72 hours: 14.0% (restricted) vs 14.9% (liberal); aOR 0.92 (95% CI 0.84–1.01), P=0.07.
  • High policy adherence (≈91% restricted vs 93% liberal) and no spontaneous reports of intraoperative awareness.
  • Suggests small potential effects; policy-level restriction alone may be insufficient to reduce delirium.

Methodological Strengths

  • Large pragmatic cluster randomized crossover design across 20 centers with patient and assessor blinding.
  • High adherence to policy assignments and standardized delirium assessments in routine care.

Limitations

  • Borderline nonsignificant primary result (P=0.07) and cluster policy-level intervention may dilute patient-level effects.
  • Delirium detection relied on routine care tools; potential underdetection or inter-site variability.

Future Directions: Patient-level randomized trials targeting high-risk individuals and multimodal perioperative delirium prevention bundles are warranted; explore dose-response and alternative sedative strategies.

IMPORTANCE: Delirium is common after cardiac surgery and associated with adverse outcomes. Intraoperative benzodiazepines may increase postoperative delirium but restricting intraoperative benzodiazepines has not yet been evaluated in a randomized trial. OBJECTIVE: To determine whether an institutional policy of restricted intraoperative benzodiazepine administration reduced the incidence of postoperative delirium. DESIGN, SETTING, AND PARTICIPANTS: This pragmatic, multiperiod, patient- and assessor-blinded, cluster randomized crossover trial took place at 20 North American cardiac surgical centers. All adults undergoing open cardiac surgery at participating centers during the trial period were included through a waiver of individual patient consent between November 2019 and December 2022. INTERVENTION: Institutional policies of restrictive vs liberal intraoperative benzodiazepine administration were compared. Hospitals (clusters) were randomized to cross between the restricted and liberal benzodiazepine policies 12 to 18 times over 4-week periods. MAIN OUTCOMES AND MEASURES: The primary outcome was the incidence of delirium within 72 hours of surgery as detected in routine clinical care, using either the Confusion Assessment Method-Intensive Care Unit or the Intensive Care Delirium Screening Checklist. Intraoperative awareness by patient report was assessed as an adverse event. RESULTS: During the trial, 19 768 patients (mean [SD] age, 65 [12] years; 14 528 [73.5%] male) underwent cardiac surgery, 9827 during restricted benzodiazepine periods and 9941 during liberal benzodiazepine periods. During restricted periods, clinicians adhered to assigned policy in 8928 patients (90.9%), compared to 9268 patients (93.2%) during liberal periods. Delirium occurred in 1373 patients (14.0%) during restricted periods and 1485 (14.9%) during liberal periods (adjusted odds ratio [aOR], 0.92; 95% CI, 0.84-1.01; P = .07). No patient spontaneously reported intraoperative awareness. CONCLUSIONS AND RELEVANCE: In intention-to-treat analyses, restricting benzodiazepines during cardiac surgery did not reduce delirium incidence but was also not associated with an increase in the incidence of patient-reported intraoperative awareness. Given that smaller effect sizes cannot be ruled out, restriction of benzodiazepines during cardiac surgery may be considered. Research is required to determine whether restricting intraoperative benzodiazepines at the patient level can reduce the incidence of postoperative delirium. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03928236.